The Atari ST is a line of home computers from Atari Corporation, and the successor to the Atari 8-bit family. The first ST model, the 520ST, was released in June 1985. "ST" officially stands for "Sixteen/Thirty-two",[1] which referred to the Motorola 68000's 16-bit external bus and 32-bit internals. The Atari ST is the first personal computer to come with a bit-mapped color GUI,[2] using a version of Digital Research's GEM released in February 1985.[3] The 1040ST, released in 1986, is the first personal computer to ship with a megabyte of RAM in the base configuration, and also the first with a cost-per-kilobyte of less than USD$1.[4]

Jay Miner, one of the original designers for the custom chips found in the Atari 2600 and Atari 8-bit family, tried to convince Atari management to create a new chipset for a video game console and computer. When his idea was rejected, Miner left Atari to form a small think tank called Hi-Toro in 1982 and began designing the new "Lorraine" chipset. The company, which was later renamed Amiga Corporation, was pretending to sell video game controllers to deceive competition while it developed a Lorraine-based computer.[9]

Amiga ran out of capital to complete Lorraine's development, and Atari, owned by Warner Communications, paid Amiga to continue development work. In return Atari received exclusive use of the Lorraine design for one year as a video game console. After one year Atari would have the right to add a keyboard and market the complete computer, designated the 1850XLD. As Atari was heavily involved with Disney at the time, it was later code-named "Mickey", and the 256K memory expansion board was codenamed "Minnie".[10]

After leaving Commodore International in January 1984 Jack Tramiel formed Tramel (not Tramiel!) Technology with his sons and other ex-Commodore employees, and in April began planning a new computer. The company initially considered the National SemiconductorNS320xx microprocessor, but was disappointed with its performance.[11][12] This started the move to the 68000.

Tramiel learned that Warner wanted to sell Atari, which in mid-1984 was losing about a million dollars per day.[13] Interested in Atari's overseas manufacturing and world wide distribution network for his new computer, Tramiel negotiated with Warner in May and June 1984. He secured funding and bought Atari's Consumer Division (which included the console and home computer departments) in July. As executives and engineers left Commodore to join Tramiel's new Atari Corporation, Commodore responded by filing lawsuits against four former engineers for theft of trade secrets.

The Tramiels did not purchase the employee contracts when they bought the assets of Atari Inc., so one of their first acts was to interview Atari Inc. employees to decide who to hire at what was essentially a brand new company. This company was originally called TTL (Tramiel Technologies Limited), then renamed Atari Corp. At the time of the purchase of Atari Inc's assets, there were roughly 900 employees remaining from a high point of 10,000. After the interviews, approximately 100 employees were hired to work at Atari Corp.

At one point a promising sound processor called AMY was a planned component for the new ST computer design, but the chip's design had issues and needed more time to complete. The Tramiels were already running on a slim budget and an extremely aggressive time line, so AMY was dropped in favor of an off the shelf Yamaha sound chip.

It was during this time in late July/early August that Leonard Tramiel discovered the original Amiga contract, which required Amiga Corporation to deliver the Lorraine chipset to Atari on June 30, 1984. Amiga Corp. had sought more monetary support from investors in spring 1984 (among them Tramel Technology, which wished to replace nearly everyone at Amiga).

Having heard rumors that Tramiel was negotiating to buy Atari, Amiga Corp. entered into discussions with Commodore. The discussions led to Commodore wanting to purchase Amiga Corporation outright, which Commodore believed would cancel any outstanding contracts, including Atari's. Instead of Amiga Corp. delivering Lorraine to Atari, Commodore delivered a check of $500,000 to Atari on Amiga's behalf, in effect returning the funds Atari invested into Amiga for the chipset. Tramiel countersued Amiga Corp. on August 13, 1984. He sought damages and an injunction to bar Amiga (and effectively Commodore) from producing anything with its technology.

At Commodore, the Amiga team was in limbo during the summer of 1984 because of the lawsuit. No word on the status of the chipset, the Lorraine computer, or the team's fate was known. In the fall of 1984, Commodore informed the team that the Lorraine project was active again, the chipset was to be improved, the operating system developed, and the hardware design completed. While Commodore announced the Amiga 1000 with the Lorraine chipset in July 1985, the delay gave Atari, with its many former Commodore engineers, time to deliver the first Atari ST units in June 1985. In March 1987, the two companies settled the dispute out of court in a closed decision.[11][14]

With the hardware design nearing completion, the Atari team started looking at solutions for the operating system. Soon after the Atari buyout, Microsoft approached Tramiel with the suggestion that they port Windows to the platform, but the delivery date was out by about two years, far too long for their needs. Another possibility was Digital Research, who was working on a new GUI-based system then known as Crystal, soon to become GEM. Another option was to write a new operating system in-house, but this was rejected as Atari management was unsure whether the company had the required expertise to do so.[11]

Digital Research was fully committed to the Intel platform, so a team from Atari was sent to the Digital Research headquarters to work with the "Monterey Team" which comprised a mixture of Atari and Digital Research engineers. Atari's Leonard Tramiel was the Atari person overseeing "Project Jason" (a.k.a. — The Operating System) for the Atari ST line of computers. The name came from the original designer and developer, Jason Loveman. Tim Oren has an article describing the history of the project, from his series "Professional GEM".

GEM was initially based on CP/M-68K, essentially a direct port of CP/M to the 68000. By 1985, CP/M was becoming increasingly outdated in comparison to MS-DOS 2.0; for instance, CP/M did not support sub-directories. Digital Research was also in the process of building a new DOS-like operating system specifically for GEM, GEMDOS, and there was some discussion of whether or not a port of GEMDOS could be completed in time for product delivery in June. The decision was eventually taken to port it, resulting in a GEMDOS file system which became part of TOS (The Operating System and colloquially known as the Tramiel Operating System). This was beneficial as it gave the ST a fast, hierarchical file system, essential for hard drive storage disks, plus programmers had function calls similar to the IBM PC DOS.

Besides the original TOS Operating system, a number of third party OSes were developed or ported to the Atari ST. Among Unix Clones, Idris, Minix had an Atari ST port and the Mint OS was developed specifically for the Atari ST.

InfoWorld described prototypes shown at computer shows as a "typical Commodore-64 style, corner-cutting, low-cost Jack Tramiel product",[16] but Atari unexpectedly displayed the ST at COMDEX in May.[17] Due to its similarities to the original Apple Macintosh and Tramiel's role in its development, it was quickly nicknamed the "Jackintosh".[12] Atari's rapid development of the ST amazed many,[11][12] but others were more skeptical, citing the ST's "cheap" appearance, Atari's uncertain financial health, and the poor relations the Tramiel-led Commodore had with software developers.[12][18][17]

As early as 1981 Adam Osborne wrote that while Tramiel "deserves credit for what he has been able to accomplish", "the microcomputer industry abounds with horror stories describing the way Commodore treats its dealers and its customers."[19] In 1984 Ahoy! had written, before he purchased Atari, that Tramiel "had never been able to establish very good relations with computer dealers ... Under his reign, computer retailers have accused Commodore of treating them as harshly as if they were suppliers or competitors".[20]Computer Gaming World stated that his poor reputation likely made computer stores reluctant to deal with Atari, hurting the company's distribution of the ST.[21] One retailer said, "If you can believe Lucy when she holds the football for Charlie Brown, you can believe Jack Tramiel",[22] and another said that because of its experience with Tramiel "Our interest in Atari is zero, zilch".[23] Observers criticized the company's erratic discussion of its stated plans for the new computer, quickly shifting from using mass merchandisers to specialty computer stores to both; Atari executives could not name any computer stores that would carry the ST when asked at COMDEX. One analyst stated after attending a meeting with the company, "We've seen marketing strategies changed before our eyes".[17]

Tramiel's poor reputation also influenced potential developers of software for the Atari ST, with one stating that "Dealing with Commodore was like dealing with Attila the Hun. I don't know if Tramiel will be following his old habits ... I don't see a lot of people rushing to get software on the machine."[12] The majority of software companies were hesitant to support another platform beyond the IBM PC, Apple, and Commodore 64; "These days, if I were a consumer, I'd stick to companies [Apple and IBM] I know will be around", said Philippe Kahn of Borland.[24]The New York Times reported after COMDEX that "more than 100 software titles will be available for the machine, most written by small software houses that desperately need work".[17]

Trip Hawkins of Electronic Arts said "I don't think Atari understands the software business. I'm still skeptical about its resources and its credibility." Although Michael Berlyn of Infocom promised that his company would quickly publish all of its games for the new computer, he doubted that many others would soon do so. Other companies such as Spinnaker Software and Lifetree Software were more positive. Both promised to soon release ST software, with the former reporting that "Atari has a vastly improved attitude toward software developers. They are eager to give us technical support and machines", and the latter stating "we are giving Atari high priority". Some, like Software Publishing Corporation, were unsure of whether to develop for the ST or the Amiga,[18] while John C. Dvorak wrote that the public saw both Commodore and Atari as selling "cheap disposable" game machines.[25]

Atari ST advertisements stated "America, We Built It For You", and quoted Atari president Sam Tramiel: "We promised. We delivered. With pride, determination, and good old ATARI know how".[26] Although Atari was out of cash, sales of its 8-bit computers were "very, very slow" according to Jack Tramiel, and employees feared that he would shut the company down. The 520ST shipped during spring 1985 to the press, developers, and user groups, and in early July 1985 for general retail sales, saving the company.[11][27][23] By November the company stated that it had sold more than 50,000 520 STs, "with U.S. sales alone well into five figures".[28] The machine had gone from concept to store shelves in a little under a year. Atari had originally intended to release versions with 128 kB and 256 kB of RAM as the 130ST and 260ST respectively. However, with the OS loaded from floppy into RAM, there would be little or no room left over for applications to run. The 260ST did make its way into Europe on a limited basis.

The ST supports a monochrome or color monitor. The color hardware supports two different resolutions, 320 × 200 with 16 out of 512 colors, or 640 × 200 with 4 out of 512 colors. The monochrome monitor was less expensive, and has a single resolution of 640 × 400. Due to its higher vertical resolution and noninterlaced operation at 70 Hz, the monochrome monitor was better suited to business applications. The attached monitor determines available resolutions, so software either supports both types of monitors or only works with one.[29] Color is required by a majority of games. Unlike the Amiga, Commodore 64, and Atari 8-bit computers, the ST does not have hardware-supported sprites.

The early ST systems have no battery-backed clock so time needs to be set after turning on. Early models shipped with Atari Logo and TOS on disk; the operating system occupies 206K RAM, but were designed with four ROM sockets to make for easy upgrading to the future ROM-based TOS.[29] These became available only a few months later, and were included in all new machines, as well as being available to upgrade older machines. By late 1985 the machines were also upgraded with the addition of an RF modulator (for TV display), a version known as the 520STM.

Atari had originally intended to include GEM's GDOS (Graphical Device Operating System), which allowed programs to send GEM VDI (Virtual Device Interface) commands to drivers loaded by GDOS. This allowed developers to send VDI instructions to other devices simply by pointing to it. However, GDOS was not ready at the time the ST started shipping, and was included in software packages and later ST machines. Later versions of GDOS supported vector fonts.

The face of J.R. "Bob" Dobbs

A limited set of GEM fonts were also included within the ROMs. These fonts also feature an addition: The standard 8x8 pixel graphical character set for the ST (the main in-ROM "font" for GEM, and text-mode TOS operations in color modes) contains, following all the standard numbers, letters, symbols and accented characters, four unusual characters. These can be placed together in a square, forming a basic but recognisable facsimile of the face of J. R. "Bob" Dobbs, the figurehead of the Church of the Subgenius.[30]

The ST was less expensive than most machines, including the Macintosh Plus, and tended to be faster than most.[31] Largely as a result of the price/performance factor, the ST would go on to be a fairly popular machine, notably in European markets where the foreign-exchange rates amplified prices. Indeed, the company's English advertising strapline of the era was "power without the price". In fact, an Atari ST and terminal emulation software was much cheaper than a DigitalVT220 terminal, which was commonly needed by offices with central computers.

The original 520ST case design was created by Ira Velinsky — Atari's chief Industrial Designer.[32] The ST is basically wedge shaped, featuring bold angular lines and a series of grilles cut into the rear for airflow. The keyboard has soft tactile feedback and rhomboid-shaped function keys across the top. The 520ST is an all-in-one unit, similar to earlier home computers like the Commodore 64. By the time the 520ST reached the market, however, market and IBM compatibility concerns demanded a keyboard with cursor keys and a numeric keypad. For this reason, the 520ST ended up significantly larger than previous popular all-in-one machines like the Commodore 64.

The 520ST uses an external "brick" power supply, floppy disk, monitor and mouse. Even basic system setups thus suffer from cable spaghetti, a problem future versions would address to one degree or another. Early 520ST owners became accustomed to the "Atari Twist" and the "Atari Drop" service procedures[citation needed]. The "Atari Twist" seemed to help discharge built-up static electricity (Atari soldered-down the metal shielding to fix the problem) while the "Atari Drop" appeared to help re-seat chips which may have become partially unseated over time.

Because of its bi-directional design, the Centronics printer port can be used for joystick input, and several games make use of available adaptors that plugged into the printer socket, providing two additional 9-pin joystick ports.

Atari initially used single-sided disk drives that could store up to 360 kB. Later drives were double-sided versions that stored 720 kB. Due to the early sales of so many of the single-sided drives, some commercial software, particularly games, shipped by default on single-sided disks, even supplying two 360kB floppies instead of a single double-sided one, for fear of alienating early adopters[citation needed]. The problem was exacerbated by the early drive's single read/write head being on the "wrong" side of the disc - that is, reading/writing the same side of the disc as a more standard 720kB drive's "second" head ("head 1") instead of its "first" ("head 0"). The boot sector and FAT was typically written to "side 0" by double-sided drives (in both STs and other marques fitted with 3.5" drives), so owners of single-sided machines could not read any useful data from a standard double-sided disc at all, not even the root directory listing, and might well mistakenly end up reformatting just one side of a seemingly "faulty" disc as a result.

ST magazines wishing to cater to the entire audience while still supplying a large amount of material on a single cover disc had to adopt innovative custom formats to work around this problem, forcing the bootsector and FAT onto "side 1", along with the disc's main feature program, and tucking supplemental programs onto "side 0" (typically falsely renamed "side B", in allusion to classic 45rpm singles), "inside" a particular file folder which would only open successfully for owners of 720kB drives. Owners of single-sided drives were encouraged, if they wished to gain access to "side B", to send the original coverdisk(s) back to the publisher with a token fee for postage and duplication, for which they would be sent a set of single-sided discs containing the full software complement. This scheme was also operated by some producers of productivity software in later years, mirroring the PC situation where software would ship by default on a particular disc format (3.5" or 5.25", double or high density) and a customer who bought the wrong type could have it replaced by mail order.

Another early sticking point with the ST's floppy drives was that, whilst double-sided drive equipped STs could happily read discs formatted under MS-DOS on IBM PCs, PCs could not themselves read Atari disks, because the initial versions of TOS could recognise, read, and write to - but not themselves create - discs in the same particular specification used and indeed demanded by MS-DOS (single-sided Atari drives were completely incompatible in either direction, as MS-DOS never officially supported single-sided 3.5" hardware, and still placed its filesystem information on "side 0").[clarification needed] Achieving successful data interchange between the two platforms using floppies thus required pre-formatting dedicated file transfer discs under MS-DOS, and copying the necessary data onto them from any unsuitable Atari formatted discs. This formatting issue was soon resolved by the emergence of third-party formatting and file copier software, MS-DOS disc imaging software capable of reading the unusual formats used by the ST and various other machines (such as the Commodore Amiga) and, a few years later, Atari's own version 1.4 (and later) TOS upgrades.

Atari later upgraded the basic design in 1986 with the 1040STF (also written STF). The machine is generally similar to the earlier 520ST, but moved the power supply and a double-sided floppy drive into the rear of the housing of the computer, as opposed to being external. This added to the size of the machine, but reduced cable clutter in the back. However, the joystick/mouse ports, formerly on the right side of the machine where the disk now sat, had to be moved to an awkward location in a cramped niche underneath the keyboard.

The 1040ST was the first personal computer shipped with a base RAM configuration of 1 MB. When the list price was reduced to $999 in the U.S. it appeared on the cover of BYTE in March 1986 as the first computer to break the $1000/megabyte price barrier;[11][4]Compute! noted that, in fact, the 1040ST was the first computer to break the $2500/megabyte price barrier.[33] However, the ST remained generally the same internally over the majority of its several-year lifespan. The choice of model numbers was inherited from the model numbers of the XE series of the Atari 8-bit family of computers. A limited number of 1040STFs shipped with a single-sided floppy drive.[citation needed]

The same basic design was also used for a cut-down version, the 512 kB 520STFM, which replaced the earlier 520ST models in the market. The early 'STF' machines lack the 'M' modulator that allows a TV to be used and will only work with a monitor.

Initial sales were strong, especially in Europe where Atari sold 75% of its computers. Germany became Atari's strongest market,[11] with small business users using them for desktop publishing and CAD.

To address this growing market segment, Atari came up with the ST1. Debuted at Comdex in 1986, it was received favorably. Renamed the Mega, this new machine includes a high-quality detached keyboard, a stronger case to support the weight of a monitor, and an internal bus expansion connector. A 20 MB hard drive called the SH204 could be purchased as an option and stacked below or above the main case of the Mega. The upcoming SLM804laser printer would not come with a processor or memory, reducing costs. It would attach to the Mega through the ST DMA port and require the Mega computer to render the pages. As TOS was not a multitasking OS, this meant the computer could not be used while printing. Initially equipped with 2 or 4 MB (a 1 MB version, the Mega 1 would later follow), the Mega machines would complement the Atari laser printer for a low-cost desktop publishing package, which received acclaim and was featured on the cover of Computer Shopper magazine.

A custom blitter co-processor was to be included to speed the performance of some graphics operations on the screen, but due to delays it was eventually released on the Mega 2 and Mega 4 machines. Developers wanting to use it had to detect for it in their programs because it was not present on all machines. However, properly written programs using the screen VDI commands can use the blitter seamlessly, since GEM API is a higher-level interface to TOS.

In late 1989, Atari released the 520STE and 1040STE (also written STE), enhanced version of the ST with improvements to the multimedia hardware and operating system. It features an increased color palette of 4096 colors from the ST's 512 (though the maximum displayable palette of these without programming tricks was still limited to 16 in the lowest 320x200 resolution, and even fewer in higher resolutions), Genlock support, and a graphics co-processor chip called Blitter, which can quickly move large blocks of data (most particularly, graphics sprites) around in RAM. It also included a new 2-channel digital sound chip that could play 8-bit stereo samples in hardware at up to 50kHz. Two enhanced joystick ports (EJP) were added (two normal joysticks can be plugged into each port with an adapter), with the new connectors placed in more easily accessed locations on the side of the case. The enhanced joystick ports were re-used in Atari's Jaguar console, and are compatible. RAM was now much more simply upgradable via SIMMs. CPU speed was unchanged and ran at 8 MHz.

The STE models initially had software and hardware conflicts resulting in some applications and video games written for the ST line being unstable or even completely unusable, primarily caused by programming direct hardware calls which bypassed the operating system. Sometimes incompatibility could be solved by expanding the RAM. Furthermore, even having a joystick plugged in would sometimes cause strange behavior with a few applications (such as the WYSIWYG word-processor application First Word Plus).

The STE was the first Atari with PCM audio, which was probably one of the most attractive features of the machine. It has the ability to play back 8-bit (signed) samples using the SDMA at the following frequencies: 6258Hz, 12517Hz, 25033Hz and 50066Hz—sampling frequencies above audio CDs, although, at only 8-bit resolution. The channels are arranged as either a mono track or a track of LRLRLRLR... bytes.

Very little use was made of the extra features of the STE: STE-enhanced and STE-only software were rare, generally being limited to serious art, CAD, or music applications, with very few games taking advantage of the hardware, not present on most machines.

The last STE machine, the Mega STE, is an STE in a grey Atari TT case that had a switchable 16 MHz, dual-bus design (16-bit external, 32-bit internal), optional Motorola 68881FPU, built-in 3½" floppy disk drive, VME expansion slot, a network port (very similar to that used by Apple's LocalTalk) and an optional built-in 3½" hard drive. It also shipped with TOS 2.00 (better support for hard drives, enhanced desktop interface, memory test, 1.44 MB floppy support, bug fixes). It was marketed as more affordable than a TT but more powerful than an ordinary ST.

In 1990, Atari released the high-end workstation-oriented Atari TT030, based on a 32 MHz Motorola 68030 processor. The "TT" name ("Thirty-two/Thirty-two") continued the nomenclature system as the 68030 chip had full 32-bit wide buses both internally and externally. Originally planned with a 68020 CPU, the TT included improved graphics and more powerful support chips. The case was a new design with an integrated hard-drive enclosure.

The final ST computer is the multimedia-capable Atari Falcon030. Like the TT, this was also 68030-based, operating at 16 MHz, but with improved video modes and an on-board Motorola 56001 audio digital signal processor. The Falcon, like the Atari STE, supports sampling frequencies above 44.1 kHz; the sampling master clock is 98340 Hz, which can be divided by a number between 2 and 16 to get the actual sampling frequencies. Apart from these frequencies, it is also able to play the STE sample frequencies (up to 50066 Hz) in 8 or 16 bit, mono/stereo, all by using the same DMA interface as the STE, with a few additions. The Falcon can both play back and record samples; it has 8 mono channels / 4 stereo channels; thus this allowed musicians to use the computer for harddisk recording. Although the 68030 microprocessor is capable of using 32-bit memory, the Falcon uses a 16-bit bus which affects performance, but also served to reduce its cost. In another cost-reduction measure, Atari shipped the Falcon in an inexpensive case much like that of the STF and STE. Aftermarket upgrade kits were available that allowed the Falcon to be put in a desktop or rack-mount case, with the keyboard separate.

Released in 1992, the Falcon was discontinued by Atari the following year. In Europe, C-Lab licenced the Falcon design from Atari, and released the C-Lab Falcon Mk I (the same as Atari's Falcon except for some slight modifications to the audio circuitry), Mk II (as Mk I but with an internal 500 MB SCSI hard disk) and Mk X (as Mk II but in a desktop case).

In 1993, Atari ceased development on the ST computers to focus on the Jaguar.

Following the exit of Atari from the computer market, Medusa Computer Systems manufactured some powerful 3rd-party Atari Falcon/TT-compatible machines that used 68040 and 68060 processors, based on multimedia (particularly audio, but also video), CAD, and office uses.

Despite the lack of a hardware supplier, there is a small active community dedicated to keeping the ST platform alive. There have been advancements in the operating system, software emulators (for Windows, Mac, & Linux), and some hardware developments. There are accelerator cards, such as the CT60 & CT63, which is a 68060 based accelerator card for the Falcon, and there is the Atari Coldfire Project, which aims at developing an Atari-clone based on the Coldfire processor. Milan Computer of Germany also made 68040 and 68060-based Atari clones that can run either Atari TOS 4.5 or Milan Computer's MultiTOS operating system.

As with the Atari 8-bit computers,[34][35][36][37] software publishers attributed their reluctance to produce Atari ST products in part to—as Compute! reported in 1988—the belief in the existence of a "higher-than-normal amount of software piracy".[38][39] That year WordPerfect threatened to discontinue the Atari ST version of its word processor because the company discovered that pirate bulletin board systems (BBSs) were distributing it, causing ST-Log to warn that "we had better put a stop to piracy now ... it can have harmful effects on the longevity and health of your computer".[37] In 1989 magazines published a letter by Gilman Louie, head of Spectrum Holobyte. He stated that he had been warned by competitors that releasing a game like Falcon on the ST would fail because BBSs would widely disseminate it. Within 30 days of releasing the non-copy protected ST version, the game was available on BBSs with maps and code wheels. Because the ST market was smaller than that for the IBM PC it was more vulnerable to piracy which, Louie said, seemed to be better organized and more widely accepted for the ST. He reported that the Amiga version sold in six weeks twice as much as the ST version in nine weeks, and that the Mac and PC versions had four times the sales. Computer Gaming World stated "This is certainly the clearest exposition ... we have seen to date" of why software companies produced less software for the ST than for other computers.[40][41]

The ST has built-in MIDI ports, and there was plenty of MIDI-related software for use professionally in music studios, or by amateur enthusiasts. The popular Windows/Macintosh applications Cubase and Logic Pro originated on the Atari ST (the latter as Notator Logic, preceded by Creator, Notator and Notator-SL). Another popular and powerful ST music sequencer application, Dr. T's KCS, contains a "Multi-Program Environment" that allows ST users to run other applications, such as the synthesizer patch editing software XoR (now known as Unisyn on the Macintosh), from within the sequencer application.[42]

Music tracker software was popular on the ST, such as the TCB Tracker, aiding the production of quality music from the Yamaha synthesizer ('chiptunes').

An innovative music composition program that combines the sample playing abilities of a tracker with conventional music notation (which was usually only found in MIDI software) is called Quartet (after its 4-note polyphonic tracker, which displays one monophonic stave at a time on color screens).

Due to the ST having comparatively large amounts of memory for the time, sound sampling packages became a realistic proposition. The Microdeal Replay Professional product features a sound sampler that cleverly uses the ST cartridge port to read in parallel from the cartridge port from the ADC. For output of digital sound, it uses the on-board frequency output, sets it to 128 kHz (inaudible) and then modulates the amplitude of that.

Another program that had good success on the ST platform is MasterTracks Pro from Passport Designs, of Half Moon Bay, CA., that was first put out by Don Williams for the Macintosh. When the ST died, a PC version continued that one could port MIDI to using the generic .MID format. GVox bought out Passport, and continues the program for Windows and Mac OS along with the other Passport product, the notation program Encore.

In addition to the sound-sampling functionalities, the availability of software packages with MIDI support for music composition and efficient sound analysis contributed to make the Atari ST a forerunner of later computer-based all-in-one studios.

The ST's low cost, built-in MIDI ports, and fast, low-latency response times made it a favorite with musicians:

Atari Teenage Riot named itself after the brand and programmed most of their music on an Atari ST. Including the entire album Is This Hyperreal? (June, 2011).

The Fatboy Slim album You've Come A Long Way, Baby has an Atari ST in the large foldout picture of Fatboy Slim's studio.

In the Paris performance of Jean Michel Jarre's album Waiting for Cousteau, musicians have attached Atari ST machines with unidentified MIDI software to their keyboards, as could be seen in the TV live show and video recordings.

Graphics programs such as NEOchrome, Degas & Degas Elite, Canvas, Deluxe Paint, and Cyber Paint (which author Jim Kent would later evolve into Autodesk Animator)[44] featured advanced features such as 3D design and animation. One paint program, Spectrum 512, uses the ST's rapid palette switching ability to expand the maximum number of colors to be displayed on-screen at once to 512[44] (up to 46 in each scan line — the STE never had a Spectrum4096, but other more minor applications filled this speciality niche, one even going so far as to program the shifter chip to palette shift at a rate enabling a display of 19200 colors).

3D computer graphics applications (like Cyber Studios CAD-3D, which author Tom Hudson would later develop into Autodesk3D Studio[45][46]), brought 3D modelling, sculpting, scripting, and most important, computer animation (using delta-compression) to the desktop. Video-capture and -editing applications using special video-capture 'dongles' connected using the cartridge port — low frame rate, mainly silent and monochrome, but progressing to sound and basic color (in still frames) by the end of the machine's life. At the end, Spectrum 512 and CAD-3D teamed up to produce realistic 512-color textured 3D renderings, but processing was slow, and Atari's failure to deliver a machine with a math coprocessor had Hudson and Yost looking towards the PC as the future before a finished product could be delivered to the consumer.[44]

The Atari ST was the computer upon which today's prevalent graphical touchscreen point of sale software for restaurants was originally developed. This software was created by Gene Mosher under the ViewTouch[47] copyright and trademark. It does not feature the Atari ST's GEM graphical user interface but, instead, features an application specific graphical user interface and widget framework which he developed using, in part, the Neochrome paint program.

The initial development kit from Atari included a computer and manuals. At $5,000, this discouraged many from developing software for the ST. Later, the Atari Developer's Kit consisted of software and manuals (no hardware) for $300. Included with the kit were a resource kit, C compiler (first Alcyon C, then Mark Williams C), debugger, and 68000 assembler (plus the non-disclosure agreement).

The ST came bundled with a system disk that contained ST BASIC, the first BASIC for the ST. However, due to its poor performance, users favored other BASICs, such as GFA BASIC, FaST BASIC (notable for being one of the few programs to actually be supplied as a ROM cartridge instead of on disc), and the relatively famous STOS, which then inspired and led to the creation of AMOS on the Amiga, and powerful enough that it was used (with a compiler, opposed to its usual runtime interpreter) for the production of at least two commercial titles and an innumerable host of good quality shareware and public domain games. In the late years of the Atari ST Omikron Basic was bundled with it in Germany.

The ST enjoyed success in gaming due to low cost, fast performance and colorful graphics.

Notable individuals who developed games on the ST include Peter Molyneux, Doug Bell, Jeff Minter, Éric Chahi, Jez San, and David Braben. An early real-time 3D role-playing video game, Dungeon Master, was first developed and released on the ST, and was the best-selling software ever produced for the platform. Simulation games like Falcon and Flight Simulator II made use of the enhanced graphics found in the ST machines, as did many arcade ports. One game, MIDI Maze, uses the MIDI ports to connect up to 16 machines for interactive networked play. Games simultaneously released on the Amiga that had identical graphics and sound were often accused by video game magazines of simply being ST ports. The critically acclaimed game Another World was originally released for ST and Amiga in 1991 with the Polygonal engine developed on the ST and the rotoscoped animations created on the Amiga (the two games are very similar on both systems).

Garry Kasparov became the first player to register the commercial ChessBase, a popular commercial database program produced for storing and searching records of games of chess. The first version was built for Atari ST with his collaboration in January 1987.[48] In his autobiography Child of Change, he regards this facility as the most important development in chess research since printing.

Remarkably, a modest core fanbase for the system, supporting a dwindling number of good quality print magazines, survived to the mid-'90s and the birth of the modern, publicly accessible Internet as we know it. Despite the limited graphics, memory, and temporary hard-storage capabilities of the system, several email, FTP, telnet, IRC, and even full-blown graphical World Wide Web browser applications were available and usable on the ST.

There were also DOS emulators released in the late 80s. PC-Ditto came in two versions, software-only-, and a hardware version that plugs into the cartridge slot or kludges internally. After running the PC-Ditto software, a DOS boot disk is required to load the system. Both allow users to run DOS programs in CGA mode, though much more slowly than on an IBM PC. Other options are the PC-Speed (NEC V30), AT-Speed (Intel 80286) and ATonce-386SX (Intel 80386sx) hardware emulator boards.

ST Shifter"Video shift register chip"—Enables bitmap graphics using 32 kB of contiguous memory for all resolutions. Screen address has to be a multiple of 256.

ST GLU"Generalized Logic Unit"—Control logic for the system used to connect the ST's chips. Not part of the data path, but needed to bridge chips with each other.

ST MMU"Memory Management Unit"— Provides signals needed for CPU/blitter/DMA and Shifter to access dynamic ram. Even memory accesses are given to CPU/Blitter/DMA while odd cycles are reserved for DRAM refresh or used by Shifter for displaying contents of the frame buffer.

ST DMA"Direct Memory Access"—Used for floppy and hard drive data transfers. Can directly access main memory in the ST.

Very early machines included the OS on a floppy disk due to it not being ready to be burned to ROM (like the Amiga 1000 had). This early version of TOS was bootstrapped from a very small core boot ROM, but this was quickly replaced with (expanded capacity) ROM versions of TOS 1.0 when it was ready. (This change was also greatly welcomed as older ST machines with memory below 512 kB suffered, as GEM loaded its entire 192 kB code into RAM when booting the desktop). Having the OS loaded from disk was due to Atari trying to rush the machines to market without ironing out all the bugs in the OS. Soon after this change, most production models became STFs, with an integrated single- (520STF/512 kB RAM) or double-sided (1040STF/1024 kB RAM) double density floppy disk drive built-in, but no other changes. The next later models used an upgraded version of TOS: 1.02 (also known as TOS 1.2). Another early addition (after about 6 months) was an RF Modulator that allows the machine to be hooked to a color TV when run in its low or medium resolution (525/625 line 60/50 Hz interlace, even on RGB monitors) modes, greatly enhancing the machine's saleability and perceived value (no need to buy a prohibitively expensive, even if exceptionally crisp and clear, monitor). These models were known as the 520STM (or 520STM). Later F and FM models of the 520 had a built in double-sided disk drive instead of a single-sided one.

Memory: 30-pin SIMM memory slots (SIPP packages in earliest versions) allowing upgrades up to 4 MB Allowable memory sizes including only 0.5, 1.0, 2.0, 2.5 and 4.0 MB due to configuration restraints (however, 2.5 MB is not officially supported and has compatibility problems). Later 3rd-party upgrade kits allow a maximum of 14MB w/Magnum-ST, bypassing the stock MMU with a replacement unit and the additional chips on a separate board fitting over it.

Ability to synchronise the video-timings with an external device so that a video Genlock device can be used without having to make any modifications to computer's hardware

Analogue joypad ports (2), with support for devices such as paddles and light pens in addition to joysticks/joypads. The Atari Jaguar joypads and Power Pad joypads (gray version of Jaguar joypads marketed for the STE and Falcon) can be used without an adapter. Two standard Atari-style digital joysticks could be plugged into each analogue port with an adapter.

TOS 1.06 (also known as TOS 1.6) or TOS 1.62 (which fixed some major backwards-compatibility bugs in TOS 1.6) in two socketed 128 kB ROM chips.

The members of the ST family are listed below, in rough chronological order:

520ST

Original model with 512 kB RAM, external power supply, no floppy disk drive. The early models had only a bootstrap ROM and TOS had to be loaded from disk.

520ST+

early 520STs with 1 MB of RAM, but without floppy disk

260ST

originally intended to be a 256 kB variant, but actually sold in small quantities in Europe with 512 kB. Used after the release of the 520ST+ to differentiate the cheaper 512 kB models from the 1 MB models. Also because the early 520ST's were sold with TOS on disk, this ate up 192k or RAM so the machine only had around 256K left. So it made sense to call it a 260ST.

520STM

a 520ST with a built-in modulator for TV output, 512 kB RAM.

520STFM

a 520STM with a newly redesigned motherboard in a larger case with a built-in floppy disk drive (in some cases a single sided drive only), 512 kB RAM.

1040STF

a 520STFM with 1 MB of RAM and a built-in double-sided floppy disk, but without RF modulator

1040STFM

a 520STFM with 1 MB of RAM and a built-in double-sided floppy disk with RF modulator

Mega ST (MEGA 1, MEGA 2, MEGA 4)

redesigned motherboard with 1, 2 or 4 MB of RAM, respectively, in a much improved "pizza box" case with a detached keyboard. All MEGA mainboard have a PLCC socket for the Blitter chip and some early models did not include the BLiTTER chip. Included a real-time clock and internal expansion connector. Some early MEGA 2 had a MEGA 4 mainboard with half of the mem chip places unpopulated and these MEGA 2 can be upgraded by adding the additional DRAM chips and some resistors for the control lines. The MEGA 1 mainboards had a redesigned mem chip area and could not be upgraded in this way as there are only mem chip places for the 1 MByte DRAM chips.

520STE and 1040STE

a 520STFM/1040STFM with enhanced sound, the BLiTTER chip, and a 4096-color palette, in the older 1040 style all-in-one case

a portable (but definitely not laptop) version of the ST with the complete ST keyboard, an LCD screen simulating 640x400 hi-res, and a mini-trakball intended mostly for travellers and musicians because of the backlight screen and its built-in midi ports. Originally designed to operate on 12 standard C cell flashlight batteries for portability, when Atari finally realized how quickly the machine would use up a set of batteries (especially when rechargeable batteries of the time supplied insufficient power compared to the intended alkalines), they simply glued the lid of the battery compartment shut.

a later portable ST, more portable than the STacy, but sacrificing several features in order to achieve this — notably the backlight, and internal floppy disk drive. Files were meant to be stored on a small amount (one megabyte) of internal flash memory 'on the road' and transferred using serial or parallel links, memory flashcards or external (and externally powered) floppy disk to a desktop ST once back indoors. The screen is highly reflective for the time, but still hard to use indoors or in low light, it is fixed to the 640 × 400 1-bit mono mode, and no external video port was provided. For its limitations, it gained some popularity, particularly amongst musicians.

Atari TT030: new machine based on the Motorola 68030 processor running at 32 MHz, in yet another new case design with a detached keyboard. Capable of high screen resolutions with better color palettes and addressing more memory, with optional onboard hard drive (slotting onto the base as a second, smaller box). Popular with CAD and DTP communities of the time for its sheer graphical capability (its 1280x960 high resolution display only recently having become a common size on modern PCs) and processing speed.

Atari Falcon 030: another 68030 based (albeit only 16 MHz) machine like the TT, but in the STE-style case (yet again) with further upgrades to the graphics and sound, a Motorola 56000DSP for CD-quality sound recording and processing, multitasking OS (on disk) and a LocalTalk port for networking. Last computer made by Atari.

There were also some unreleased prototypes: Falcon 040 (based on a Motorola 68040, new case and slots), ST Pad/STylus (A4 (Letter paper) sized pen-operated portable ST computer, handheld and with an unlit monochrome LCD screen derived from the ST Book, forerunner of modern tablet PCs)[citation needed].